body{
    background: url(../imgs/sign-bg.jpg) no-repeat;
    background-size: 570px;
    background-position: center;

    .big{
        display: flex;
        flex-direction: column;
        align-items: center;
    }
    a{
        color: white;
        position: absolute;
        right: 20px;
        top: 20px;
    }
    h1{
        color: white;
        margin-top: 75px;
        margin-left: 20px;
        margin-bottom: 0px;
    }
    .inner{
        width: 350px;
        height: 500px;
        text-align: center;
        margin-top: 35px;
        input{
            width: 330px;
            height: 50px;
            margin-bottom: 15px;
            border-radius: 20px;
            background: rgba(255, 255, 255, 0.5);
        }
        input::-webkit-input-placeholder{
            color: #ccc;
            padding-left: 10px;
        }

        button{
            width: 330px;
            height: 50px;
            background: rgb(107, 209, 107);
            border-radius: 20px;
            color: white;
        }
        #tips{
            color: red;
            font-size: 28px;
        }
    }
}